<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <form action="w.php" method="post">
        <input type="text" name="username" placeholder="用户名"><br>
        <input type="password" name="pwd" placeholder="密码"><br>
        <input type="number" name="age" placeholder="年龄"><br>
        <input type="submit" value="提交">
        </form>

</body>
</html>